By Michael Crawford, MD, Editor
SOURCES: Chikwe J, et al. Impact of concomitant tricuspid annuloplasty on tricuspid regurgitation, right ventricular function, and pulmonary artery hypertension after repair of mitral valve prolapse. J Am Coll Cardiol 2015;65:1931-1938.
McCarthy PM. Evolving approaches to tricuspid valve surgery: Moving to Europe? J Am Coll Cardiol2015; 65:1939-1940.
When to repair the tricuspid valve in patients with moderate tricuspid regurgitation (TR) undergoing mitral valve repair is unclear. Thus, investigators from Mount Sinai in New York performed a retrospective analysis of a single surgeon’s experience between 2003 and 2011. The criteria for performing a tricuspid valve annuloplasty were: 1) if moderate TR was present pre- or intra-operatively by echocardiography, 2) if the tricuspid annulus was > 40 mm in diameter on the 4-chamber echo view, 3) if the degree of TR or the annular size was equivocal by echo, but direct inspection of the tricuspid valve at surgery suggested the leaflets were inadequate for the size of the annulus. A variety of clinical endpoints were assessed over a mean follow-up of 4 years (range 0.1-8.4 years). Patients who met criteria for tricuspid annuloplasty (n = 419) were older, had worse left ventricular (LV) function, worse right ventricular (RV) function, higher pulmonary artery pressures, and more atrial fibrillation, as compared to those who had mitral valve repair alone (n = 226). Operative mortality was 0.6% and not different in the two groups, nor was 7-year survival or reoperation for recurrent TR. Freedom from moderate TR at 7 years was 97% in the tricuspid annuloplasty group and 91% in the mitral repair-only patients (P = 0.07) and tricuspid annuloplasty was an independent predictor of freedom from moderate or greater TR (hazard ratio [HR] 0.26; 95% confidence interval [CI], 0.07-0.94, P = 0.04). Tricuspid annuloplasty was also the best independent predictor of late RV functional recovery in those with RV dysfunction pre-operatively (HR 1.4; CI, 1.06-1.96; P = 0.02). The authors concluded that in patients undergoing mitral valve repair with moderate TR or tricuspid annular dilatation, tricuspid annuloplasty is safe and is associated with improved long-term RV function.
COMMENTARY
In patients undergoing mitral valve repair with severe TR, tricuspid annuloplasty is a class I recommendation in the European Society of Cardiology and the ACC/AHA guidelines. In patients with moderate TR, the U.S. guidelines state tricuspid repair can be considered for any degree of TR if there is annular dilatation or prior right heart failure (Class IIa). The European guidelines recommend considering tricuspid repair if there is moderate TR only (Class IIa). This study followed the European guidelines (moderate TR or a large annulus) and added another criteria: with equivocal findings on echo, if the surgical inspection of the valve suggested too little tissue to cover the annulus. Using these criteria in one surgeon’s hands, tricuspid annuloplasty was performed with no increase in morbidity or mortality, which were low. In this retrospective observational study, tricuspid repair markedly reduced the incidence of long-term moderate or greater TR as compared to mitral repair alone. Also, it returned impaired RV function to the levels seen in mitral repair-alone patients. Thus, the authors believe the U.S. guidelines should copy the European guidelines and liberalize the application of tricuspid repair in patients undergoing mitral valve repair.
Tricuspid repair with mitral surgery is performed variably in the United States, ranging from 6% to 60%. McCarthy argues that the common belief in the United States that mitral valve repair will abrogate moderate TR is a myth. He advocates for U.S. surgeons to follow the European guidelines. Whether to extend the recommendations beyond moderate-to-severe TR and a large annulus (> 40 mm diameter) is less certain. In this study, equivocal echo findings prompted an inspection of the tricuspid valve at surgery, and if the surgeon thought the valve tissue was insufficient to cover the annulus, it was repaired. Why the preoperative echo would be equivocal is difficult to understand. Perhaps in some patients the transthoracic echo was of poor quality and the intra-operative echo was done after anesthesia, which can change loading conditions and decrease the severity of valve regurgitation. In this study using these expanded criteria, two-thirds of patients got a tricuspid repair. Whether this is the right proportion is debatable, but patients who received tricuspid repair did very well.